I'm fixing to put a cam in my truck, swapping actually. I'm going with a 224/227. My question is, do I need to use a different size pushrod than stock? I know I need hardened ones, but what length should I get? Thanks for the help.

 

if all you are doing is changing the cam, and going for hardended PRs,
Yes 7.4 stock replacements are what you need.

 

Even with the higher lift cam ?

 

The lift of the cam has nothing to do with it,
the base cir of the cam, the installed height of rockers (aftermarket)
and if you mill the heads, are reasons to change lenth of the PRs

 

The lift of the cam does have something to do with it because it is related to the base circle. You can't add more lift with out having a smaller base circle or the lobes wouldn't fit through the cam bearings.

 

When you think of adding lift to the cam, the extra lobe height isn't added to the top of the lobe, but rather cut away from the center. Kinda like making a tree taller by digging out the dirt from around the base.